Field of the Invention
One or more embodiments of the present invention relates to a battery pack in which a top case including a protection circuit module (PCM) is coupled to a battery cell.
Description of Related Art
Unlike primary batteries, secondary batteries are chargeable and dischargeable. Secondary batteries are used as energy sources for small-sized devices, such as cellular phones, laptop computers, and camcorders, and medium-large sized devices such as electric cars, hybrid electric cars, electric bicycles, and uninterruptible power supplies (UPS).
A lithium secondary battery is an example of the secondary battery. The lithium secondary battery may be classified into a can-type secondary battery, which has a cylindrical and square pillar shape, and a pouch-type secondary battery having flexibility according to the shape of a case accommodating an electrode assembly.
Conventionally, a battery cell accommodating an electrode assembly is electrically connected to a protection circuit module (PCM). The PCM includes a plurality of electrode taps. In a secondary battery having a square pillar shape, a positive electrode tap is electrically connected to a can or cap plate of a battery cell, and a negative electrode tap is electrically connected to an electrode terminal of the battery cell. The PCM is installed in a top case, and the top case is coupled to the battery cell.
In a battery pack having a structure as described above, there is a need to reduce assembly errors, such as defects in welding, which may be caused during a process of assembling components when a top case is coupled to a battery cell.